/*
 * Javassist, a Java-bytecode translator toolkit.
 * Copyright (C) 1999- Shigeru Chiba. All Rights Reserved.
 *
 * The contents of this file are subject to the Mozilla Public License Version
 * 1.1 (the "License"); you may not use this file except in compliance with
 * the License.  Alternatively, the contents of this file may be used under
 * the terms of the GNU Lesser General Public License Version 2.1 or later,
 * or the Apache License Version 2.0.
 *
 * Software distributed under the License is distributed on an "AS IS" basis,
 * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
 * for the specific language governing rights and limitations under the
 * License.
 */

package com.feilong.lib.javassist.expr;

import com.feilong.lib.javassist.CannotCompileException;
import com.feilong.lib.javassist.CtBehavior;
import com.feilong.lib.javassist.CtClass;
import com.feilong.lib.javassist.CtPrimitiveType;
import com.feilong.lib.javassist.NotFoundException;
import com.feilong.lib.javassist.bytecode.BadBytecode;
import com.feilong.lib.javassist.bytecode.Bytecode;
import com.feilong.lib.javassist.bytecode.CodeAttribute;
import com.feilong.lib.javassist.bytecode.CodeIterator;
import com.feilong.lib.javassist.bytecode.ConstPool;
import com.feilong.lib.javassist.bytecode.Descriptor;
import com.feilong.lib.javassist.bytecode.MethodInfo;
import com.feilong.lib.javassist.bytecode.Opcode;
import com.feilong.lib.javassist.compiler.CompileError;
import com.feilong.lib.javassist.compiler.Javac;
import com.feilong.lib.javassist.compiler.JvstCodeGen;
import com.feilong.lib.javassist.compiler.JvstTypeChecker;
import com.feilong.lib.javassist.compiler.ProceedHandler;
import com.feilong.lib.javassist.compiler.ast.ASTList;

/**
 * Array creation.
 *
 * <p>
 * This class does not provide methods for obtaining the initial
 * values of array elements.
 */
public class NewArray extends Expr{

    int opcode;

    protected NewArray(int pos, CodeIterator i, CtClass declaring, MethodInfo m, int op){
        super(pos, i, declaring, m);
        opcode = op;
    }

    /**
     * Returns the method or constructor containing the array creation
     * represented by this object.
     */
    @Override
    public CtBehavior where(){
        return super.where();
    }

    /**
     * Returns the line number of the source line containing the
     * array creation.
     *
     * @return -1 if this information is not available.
     */
    @Override
    public int getLineNumber(){
        return super.getLineNumber();
    }

    /**
     * Returns the source file containing the array creation.
     *
     * @return null if this information is not available.
     */
    @Override
    public String getFileName(){
        return super.getFileName();
    }

    /**
     * Returns the list of exceptions that the expression may throw.
     * This list includes both the exceptions that the try-catch statements
     * including the expression can catch and the exceptions that
     * the throws declaration allows the method to throw.
     */
    @Override
    public CtClass[] mayThrow(){
        return super.mayThrow();
    }

    /**
     * Returns the type of array components. If the created array is
     * a two-dimensional array of <code>int</code>,
     * the type returned by this method is
     * not <code>int[]</code> but <code>int</code>.
     */
    public CtClass getComponentType() throws NotFoundException{
        if (opcode == Opcode.NEWARRAY){
            int atype = iterator.byteAt(currentPos + 1);
            return getPrimitiveType(atype);
        }else if (opcode == Opcode.ANEWARRAY || opcode == Opcode.MULTIANEWARRAY){
            int index = iterator.u16bitAt(currentPos + 1);
            String desc = getConstPool().getClassInfo(index);
            int dim = Descriptor.arrayDimension(desc);
            desc = Descriptor.toArrayComponent(desc, dim);
            return Descriptor.toCtClass(desc, thisClass.getClassPool());
        }else{
            throw new RuntimeException("bad opcode: " + opcode);
        }
    }

    CtClass getPrimitiveType(int atype){
        switch (atype) {
            case Opcode.T_BOOLEAN:
                return CtClass.booleanType;
            case Opcode.T_CHAR:
                return CtClass.charType;
            case Opcode.T_FLOAT:
                return CtClass.floatType;
            case Opcode.T_DOUBLE:
                return CtClass.doubleType;
            case Opcode.T_BYTE:
                return CtClass.byteType;
            case Opcode.T_SHORT:
                return CtClass.shortType;
            case Opcode.T_INT:
                return CtClass.intType;
            case Opcode.T_LONG:
                return CtClass.longType;
            default:
                throw new RuntimeException("bad atype: " + atype);
        }
    }

    /**
     * Returns the dimension of the created array.
     */
    public int getDimension(){
        if (opcode == Opcode.NEWARRAY){
            return 1;
        }else if (opcode == Opcode.ANEWARRAY || opcode == Opcode.MULTIANEWARRAY){
            int index = iterator.u16bitAt(currentPos + 1);
            String desc = getConstPool().getClassInfo(index);
            return Descriptor.arrayDimension(desc) + (opcode == Opcode.ANEWARRAY ? 1 : 0);
        }else{
            throw new RuntimeException("bad opcode: " + opcode);
        }
    }

    /**
     * Returns the number of dimensions of arrays to be created.
     * If the opcode is multianewarray, this method returns the second
     * operand. Otherwise, it returns 1.
     */
    public int getCreatedDimensions(){
        if (opcode == Opcode.MULTIANEWARRAY){
            return iterator.byteAt(currentPos + 3);
        }
        return 1;
    }

    /**
     * Replaces the array creation with the bytecode derived from
     * the given source text.
     *
     * <p>
     * $0 is available even if the called method is static.
     * If the field access is writing, $_ is available but the value
     * of $_ is ignored.
     *
     * @param statement
     *            a Java statement except try-catch.
     */
    @Override
    public void replace(String statement) throws CannotCompileException{
        try{
            replace2(statement);
        }catch (CompileError e){
            throw new CannotCompileException(e);
        }catch (NotFoundException e){
            throw new CannotCompileException(e);
        }catch (BadBytecode e){
            throw new CannotCompileException("broken method");
        }
    }

    private void replace2(String statement) throws CompileError,NotFoundException,BadBytecode,CannotCompileException{
        thisClass.getClassFile(); // to call checkModify().
        ConstPool constPool = getConstPool();
        int pos = currentPos;
        CtClass retType;
        int codeLength;
        int index = 0;
        int dim = 1;
        String desc;
        if (opcode == Opcode.NEWARRAY){
            index = iterator.byteAt(currentPos + 1); // atype
            CtPrimitiveType cpt = (CtPrimitiveType) getPrimitiveType(index);
            desc = "[" + cpt.getDescriptor();
            codeLength = 2;
        }else if (opcode == Opcode.ANEWARRAY){
            index = iterator.u16bitAt(pos + 1);
            desc = constPool.getClassInfo(index);
            if (desc.startsWith("[")){
                desc = "[" + desc;
            }else{
                desc = "[L" + desc + ";";
            }

            codeLength = 3;
        }else if (opcode == Opcode.MULTIANEWARRAY){
            index = iterator.u16bitAt(currentPos + 1);
            desc = constPool.getClassInfo(index);
            dim = iterator.byteAt(currentPos + 3);
            codeLength = 4;
        }else{
            throw new RuntimeException("bad opcode: " + opcode);
        }

        retType = Descriptor.toCtClass(desc, thisClass.getClassPool());

        Javac jc = new Javac(thisClass);
        CodeAttribute ca = iterator.get();

        CtClass[] params = new CtClass[dim];
        for (int i = 0; i < dim; ++i){
            params[i] = CtClass.intType;
        }

        int paramVar = ca.getMaxLocals();
        jc.recordParams(javaLangObject, params, true, paramVar, withinStatic());

        /*
         * Is $_ included in the source code?
         */
        checkResultValue(retType, statement);
        int retVar = jc.recordReturnType(retType, true);
        jc.recordProceed(new ProceedForArray(retType, opcode, index, dim));

        Bytecode bytecode = jc.getBytecode();
        storeStack(params, true, paramVar, bytecode);
        jc.recordLocalVariables(ca, pos);

        bytecode.addOpcode(ACONST_NULL); // initialize $_
        bytecode.addAstore(retVar);

        jc.compileStmnt(statement);
        bytecode.addAload(retVar);

        replace0(pos, bytecode, codeLength);
    }

    /*
     * <array type> $proceed(<dim> ..)
     */
    static class ProceedForArray implements ProceedHandler{

        CtClass arrayType;

        int     opcode;

        int     index, dimension;

        ProceedForArray(CtClass type, int op, int i, int dim){
            arrayType = type;
            opcode = op;
            index = i;
            dimension = dim;
        }

        @Override
        public void doit(JvstCodeGen gen,Bytecode bytecode,ASTList args) throws CompileError{
            int num = gen.getMethodArgsLength(args);
            if (num != dimension){
                throw new CompileError(Javac.proceedName + "() with a wrong number of parameters");
            }

            gen.atMethodArgs(args, new int[num], new int[num], new String[num]);
            bytecode.addOpcode(opcode);
            if (opcode == Opcode.ANEWARRAY){
                bytecode.addIndex(index);
            }else if (opcode == Opcode.NEWARRAY){
                bytecode.add(index);
            }else /* if (opcode == Opcode.MULTIANEWARRAY) */ {
                bytecode.addIndex(index);
                bytecode.add(dimension);
                bytecode.growStack(1 - dimension);
            }

            gen.setType(arrayType);
        }

        @Override
        public void setReturnType(JvstTypeChecker c,ASTList args) throws CompileError{
            c.setType(arrayType);
        }
    }
}
